Congenital condition. Neurofibromatosis is an autosomal dominant genetic disease, meaning if one of your parents has the disease you have a 50% chance of inheriting the disease. There are also instances of spontaneous mutation in about half of cases where an individual has the disease but it is not seen in family members. Either way, you are born with the condition, but may not see symptoms until later.

Mostly genetic. Neurofibromatosis,mostly inherited problem, or mutation with degrees involvement from mild to severe. Neurofibroma benign tumor that originates from the nerve cell in skin or jut under the skin.Type1 usually appears in children with brown flat skin spots, freckling in armpits, and soft tumors under the skin and sometimes bone deformity.Type2 usually benign brain tumors vestibular/acoutic neuromas.